An experiment was conducted for two consecutive years during rabi season of 2014-15 and 2015-16 to manage the onion thrips using three treatment modules viz., M1- IPM module, M2- Farmers’ practice and M3-Untreated control. It has been observed that the IPM module was the best in achieving the maximum leaf growth and bulb yield in both the years (2014-15 and 2015-16) followed by farmers’ practice module.
Trang 1Original Research Article https://doi.org/10.20546/ijcmas.2018.707.336
An Integrated Approach for Management of Thrips tabaci Lindeman in
Rabi Onion under Gangetic Plains of West Bengal, India
Maimom Soniya Devi 1* and Kusal Roy 2
1 Department of Entomology, Lovely Professional University,
Phagwara-144411, Punjab, India 2
Department of Agricultural Entomology, Bidhan Chandra Krishi Viswavidyalaya
Mohanpur-741252, Nadia, West Bengal, India
*Corresponding author
A B S T R A C T
Introduction
Onion (Allium cepa L.) is one of the important
commercial vegetable crops grown in India It
is preferred by people for its distinctive
flavour and is relished mostly as “green” for
salad and Indian cuisine is incomplete without
onion There are several factors that lead to
the low productivity of onion Among these,
one of the major constraints is insect pest
Among the insect pests, onion thrips, Thrips
tabaci Lindeman has become a global pest of
increasing concern in the past three decades
(Diaz-Monatano et al., 2011) Thrips is a
regular and potential pest of onion and cause considerable yield losses as high as 90% in
terms of quality and quantity (Gupta et al.,
1984; Darmasena, 1998; Sudharma and Nair, 1999) To tackle this sucking pest menace, farmers are extensively using different types
of insecticides However, a repeated application of chemicals is not a desirable practice, as this could lead to undesirable resistance problems To avoid further resistance in this pest, different non chemical methods need to be evaluated Multi-pronged
International Journal of Current Microbiology and Applied Sciences
ISSN: 2319-7706 Volume 7 Number 07 (2018)
Journal homepage: http://www.ijcmas.com
An experiment was conducted for two consecutive years during rabi season of 2014-15
and 2015-16 to manage the onion thrips using three treatment modules viz., M1- IPM module, M2- Farmers’ practice and M3-Untreated control It has been observed that the IPM module was the best in achieving the maximum leaf growth and bulb yield in both the years (2014-15 and 2015-16) followed by farmers’ practice module Adoption of IPM module (comprised of wheat and maize as barrier crops, seed treatment with imidacloprid
70WS and spraying of Beauveria bassiana 10 SC and spinosad 45SC at ETL) kept the plant less infested by the T tabaci An avoidable yield loss of onion bulb due to infestation
of T tabaci was estimated as 18.98% The incremental benefit cost ratio (IBCR) was
found more in IPM module than the farmers’ practice module The maximum return per
rupee investment for managing thrips in rabi onion was observed with IPM module being,
Rs 6.65
K e y w o r d s
Avoidable yield loss,
IPM module,
Incremental benefit
cost ratio, Onion
thrips, Blue sticky
trap, Population
Accepted:
20 June 2018
Available Online:
10 July 2018
Article Info
Trang 2pest management strategies that boost onion
plant health and tolerance to thrips, in addition
to suppressing thrips densities, have to be
developed for the most sustainable and
economically viable thrips management
tactics
Materials and Methods
The experiment was conducted for two
consecutive years during rabi season of
2014-15 and 202014-15-16 at the C-Block Farm of
Bidhan Chandra Krishi Viswavidyalaya,
Kalyani, Nadia, West Bengal Onion cultivar
Sukhsagar was used for the experiment
Experiment was planned in Randomized
Complete Block Design Each plot was
measuring 2.1m×1.95m (4.095 sq m) The
crop was raised following recommended
package of practices Thirty days old seedlings
were transplanted in the main field at 15cm ×
15cm spacing There were three treatment
modules viz., M1-IPM module, M2- Farmers’
practice and M3-Untreated control which were
replicated seven times
Treatment details
The details of the modules are as follows:
M 1 : IPM module
Planting of barrier crops –two continuous
inner rows of wheat (cv Purbali) followed by
two continuous outer rows of maize (cv
Kishan) were sown @ 113 kg/ha and 23 kg/ha,
respectively on all 4 sides outside the plot
covering 1.78 sq m area (20cm barrier crops
area on all four sides of a 2.1m×1.95m plot) at
20 days prior to planting of onion Hence, in
IPM module, out of 1 hectare (ten thousand
sq m) cultivable area approximately 6970 sq
m area will be available for planting of onion
crop and remaining 3030 sq m area (approx.)
will be consumed for planting of barrier crops
Onion seeds were treated with imidacloprid
70WS @ 2.45g a.i./kg of seed before sowing
in the nursery (http://skuast.org)
Spraying was initiated when thrips population reach economic threshold level (ETL), 1st
spray was given with Beauveria bassiana 10 SC@ 75g a.i./ha and 2nd spray was given with
spinosad 45SC @ 73g a.i./ha
ETL was considered as 30 thrips/plant (http://www.dogr.res.in)
Time of spray- 72 DAP and 86 DAP
M 2 : Farmers’ practice
Insecticidal spray was given at 21 days interval starting from the appearance of onion thrips Acetamiprid 20SP @ 35g
a.i./ha as 1st spray, imidacloprid 17.8SL@
35g a.i./ha as 2nd spray and acephate 75SP
@ 280g a.i./ha as 3rd spray were used Time of spray- 30 DAP, 51 DAP and 72 DAP
M 3 : Untreated control
(did not receive any insecticidal spray)
Observations recorded
Population of thrips was monitored by using blue sticky trap at weekly interval As soon as the thrips appear in the field, population of the thrips was counted at weekly interval from 10 randomly selected tagged plants per plot Thrips which were stuck on the blue sticky traps were also counted from the ten square grids using hand held magnifying lens Fresh and dry weight of bulb and number of bulbs per plot were also recorded
Onion equivalent yield (OEY) of wheat and maize grown as border crop in the IPM module plots was also calculated considering the local market price following the formula
as stated by Talukder et al., (2015) and Anjaneyulu et al., (1982)
Trang 3OEY (q/ ha) = Onion bulb yield (q/ha) +
Grain yield of wheat (q/ha) × Price of wheat grain (Rs./q)
+
Grain yield of maize (q/ha) × Price of maize
grain (Rs./q)
Statistical analysis
Analysis of variance was done according to
RCBD at 5% level of probability (Gomez and
Gomez, 1984) Assessment of avoidable loss
of bulb yield due to infestation of T tabaci in
onion cv Sukhsagar was worked out using the
concept given by Roy et al., 2008 and Basavaraju et al., 2009
% avoidable yield loss = (Dry bulb yield in IPM module - Dry bulb yield in untreated control) × 100
Dry bulb yield in IPM module
Results and Discussion
population of thrips on onion crop during
rabi, 2014-15 and 2015-16
The effect of management modules on
population of thrips of onion crop during rabi,
2014-15 and 2015-16 are presented here
(Table 1-4) Data indicated that there were no
populations of thrips in IPM module (M1) till
37 DAP in both the years of experimentation
Thrips populations were detected first on the
onion plant at 30 DAP (Table 1) and the
spraying of acetamiprid 20SP @ 35g a.i./ha
was initiated on that day at the plots receiving
farmers’ practice module of thrips
management
At 30 DAP, in 2015-16 none of the modules
showed any significant differences among
them with regard to number of thrips per plant
while, significant differences were observed in
2014-15
The non-significant effect on population of
thrips was noted at the time of their initiation
i.e during 30 DAP Similar observation was
earlier cited by Tripathy et al., (2013), though
pooled data (2014-15 and 2015-16) of thrips
population at 30 DAP revealed significant
variations among treatment modules
Significant differences in thrips population per plant had been observed among modules from
37 DAP to 100 DAP (Table 1-4) in both the years of the study except second year where thrips population did not reveal significant differences at 58 DAP and 86 DAP (Table 1) Pooled data however exhibited significant differences on occurrences of thrips per plant (Table 1–4)
Thrips populations were always recorded maximum with untreated control (Table 1-4) The number of thrips per plant was minimum with IPM module until 58 DAP from their emergence on the onion crop (Table 2) The better efficacy upto 58DAP in IPM module might be due to border crop effect of both wheat and maize As thrips are weak fliers and carried by wind, planting barrier crop like maize and wheat could effectively block or reduce adult thrips reaching onion plant
(Tripathy et al., 2013)
The use of barrier crops (2 rows of maize, the outer rows + 2 rows of wheat, the inner rows)
as advocated in the present IPM module was also earlier adopted by Srinivas and Lawande (2006) They observed very effective blocking
of adult thrips by the barrier crops which are
in conformity with the present findings and showing the usefulness of barrier crop in restricting the entry of onion thrips from
Trang 4adjoining areas Thereafter, from 65 DAP to
72 DAP, thrips populations per plant in IPM
module plots took upper hand over plots
receiving farmers’ practice module of thrips
management tactics (M2) (Table 2-3) Module
comprising IPM tactics could able to restrict
the buildup of T tabaci population below
economic threshold level till 65 DAP At 72
DAP, when T tabaci population crossed the
ETL (30thrips/plants), the 1st foliar spray of
Beauveria bassiana 10SC @ 75g a.i./ha was
given in IPM module plots Subsequent two
sprays of imidacloprid 17.8SL @ 35g a.i./ha
as 2nd spray and acephate 75SP @ 280g a.i./ha
as 3rd spray were advocated in farmers’
practice module at 51 DAP and 72 DAP,
respectively
After a first peak of T tabaci population at 72
DAP, a second peak of T tabaci population at
86 DAP were observed (Table 3) Hence, a
second round of foliar spray with spinosad
45SC @ 73g a.i./ha was given in IPM module
plots No additional sprays were given in
farmers’ practice plots Insecticidal sprays
advocated in farmers’ practice module could
not able to check the buildup of T tabaci
population much over the period
After initiation of insecticidal spray in IPM
module at 72 DAP, thrips population became
significantly low at 79 DAP as compared to
other modules in both the years (Table 3)
Annamalai et al., (2016) evaluated bioefficacy
of commercial formulation of B bassiana
(Myco-Jaal) @ 1 × 108 spores/ml which
showed 80.90 % mortality of T tabaci B
bassiana was most effective when used early
at economic threshold level, before large
thrips populations have built up Beauveria
species is usually used as a contact
myco-insecticide but survives a relatively short
period of time when exposed on a leaf surface
(Brian, 2006) In the present study, a
significant reduction in thrips population
below ETL was observed in IPM module just
after initial spray of B bassiana and
sometimes later, an increment in population over ETL was noted This finding can suitably
justify the previous opinion of Annamalai et al., 2016 and Brian, 2006
Second round of spray at 86 DAP with
spinosad 45SC @ 73g a.i./ha in IPM module plots sharply declined the T tabaci population
at 93 DAP (Table 4) Spinosad @ 0.0135% was the most toxic against adult thrips of
onion (Mahmoud et al., 2007; Panse et al.,
2012) Pooled data also disclosed similar trend Later, all plots had general reduction of thrips population as the crop progressed towards senescence (Table 4) The findings are also in conformity with the study
conducted by Tripathy et al., (2013) who
reported that significant reduction of thrips population both in IPM module and farmers’ practices over the untreated plot
The adult population of T tabaci was also
monitored by using blue sticky trap @ 1/4.095
sq m area of plot in all the modules The population of thrips trapped in blue sticky trap
was confirmed as T tabaci by microscopic
observation (Plate 5) In both the years of
study (2014-15), no population of T tabaci
was observed in M1 module at 23 DAP (Table
5) Occurrence of T tabaci on the blue sticky
trap was first detected at 23 DAP in untreated control and farmers’ practice modules in the
1st and 2nd year, respectively (Table 5) The three modules didn’t show any significant differences in number of thrips caught per square inch area of blue sticky trap as observed from pooled data at 23 DAP (Table 5)
The number of thrips caught in blue sticky trap at 30 DAP did not reveal any significant variations in both the years The pooled data exhibited significantly least number of thrips population in IPM module plots at 30 DAP
Trang 5being, 0.1/sq inch area of trap whereas, in
farmers’ practice and in untreated control plots
mean thrips population was 0.2/sq inch area
of trap at 30 DAP (Table 5)
Starting from 37 DAP to 100 DAP, significant
differences in trapping of thrips on blue sticky
trap among management modules were
observed during the study period of 2014-15
and 2015-16 (Table 5-8) Pooled data of two
years’ observation revealed significant low
catch of T tabaci in IPM module (M1) ranging
from 0.1-7.2/ sq inch area of blue sticky trap
from 37 to 58 DAP (Table 5, 6)
The numbers of onion thrips caught during 37
to 58 DAP were usually more in the farmers’
practice and untreated control modules
Maximum population of thrips trapped during
37 to 58 DAP was ranged from 0.5-10.7/sq
inch area of blue sticky trap in untreated
control module (Table 5, 6)
Catches of adult stages of T tabaci population
in blue sticky trap were more in IPM module
as compared to farmers’ practice module at 65
DAP and 72 DAP (Table 7) Trapping of
thrips on blue sticky trap depends on the
availability of their adult stages in the crop
field It had been viewed from the pooled data
that irrespective of modules catches of T
tabaci population were more during 65 DAP
to 86 DAP except 79 DAP (Table 7, 8) At 79
DAP, number of thrips caught in trap were
low in IPM and farmers’ practice modules
whereas, in untreated control number of thrips
catches in trap increased gradually from 65 -
86 DAP without any interruption in between
(based on pooled data) This reduction in adult
thrips population may be due to application of
Beauveria bassiana 10SC@ 75g a.i./ha in
IPM module plots and acetamiprid 20SP @
35g a.i./ha in farmers’ practice module It has
also been observed from a laboratory study
during rabi season that egg to adult stage of T
tabaci on onion could be completed within
14-20 days Hence, the variable occurrences of
adult population of thrips at different time (as confirmed from trap catches) are a sign of the presence of several overlapping generations of thrips in the onion crop field
In spite of three round of insecticidal spray, the plots in farmers’ practice module always
had more population of T tabaci in
comparison to IPM module except at 65 DAP (Table 7) Crops which are without any barrier
may be reinfested by T tabaci population
from the adjoining onion crop fields Possibility of such type of instances cannot be overruled here Higher trapping of thrips in the farmers’ practice module and in untreated control module as evidenced by the data signifies the aforementioned statement
A marked decline in population of adult thrips
in IPM module were observed at 93 days after planting as the plots received a second round
of foliar spray with spinosad 45SC @ 73g
a.i./ha at 86 DAP (Table 8) Afterwards, a
general decline of adult thrips population was observed in all plots as the crop progressed towards senescence (Table 8)
Effect of thrips management modules on
yield of onion during rabi, 2014-15 and
2015-16
The production of number of onion bulbs
during rabi season of 2014-15 and 2015-16
were significantly more in IPM module as compared to untreated control being, 122/plot and 184/plot, respectively for the 1st and 2nd year (Table 9) Farmers’ practice module was followed thereafter in production of bulbs being, 119 bulbs/plot and 179 bulbs/plot, respectively for the 1st and 2nd year (Table 9) Both the mentioned modules were at par with each other
The pooled data of two years experimentation showed more number of bulbs in M1 followed
by M2 being, 153/plot and 149/plot, respectively (Table 9)
Trang 6Table.1 Effect of management modules on thrips population of onion during rabi, 2014-15 and
2015-16 (Mean of 7 replications)
2014-15
2015-16
Pooled
2014-15
2015-16
Pooled
2014-15
2015-16 Pooled
(0.0)
0.7 (0.0)
0.7 (0.0)
0.7 (0.0)
0.7 (0.0)
0.7 (0.0)
0.7 (0.0)
0.9 (0.4)
0.8 (0.2)
(0.1)
0.7 (0.1)
0.8 (0.1)
1.0 (0.7)
0.9 (0.3)
1.0 (0.5)
1.3 (1.1)
1.2 (0.9)
1.2 (1.0)
(0.2)
0.8 (0.1)
08 (0.1)
1.1 (0.7)
0.9 (0.4)
1.0 (0.5)
1.3 (1.2)
1.1 (0.8)
1.2 (1.0)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
Table.2 Effect of management modules on thrips population of onion during rabi, 2014-15 and
2015-16 (Mean of 7 replications)
2014-15
2015-16
Pooled
2014-15
2015-16
Pooled
2014-15
2015-16 Pooled
(0.2)
2.0 (3.5)
1.4 (1.9)
2.8 (7.5)
2.8 (7.6)
2.8 (7.5)
3.8 (13.7)
4.3 (18.2)
4.0 (16.0)
(3.3)
1.3 (1.3)
1.6 (2.3)
3.6 (12.2)
2.8 (7.2)
3.2 (9.7)
3.3 (10.5)
3.0 (8.8)
3.2 (9.6)
(2.9)
2.1 (3.8)
1.9 (3.3)
3.7 (13.4)
2.8 (7.6)
3.3 (10.5)
4.5 (19.4)
4.5 (19.7)
4.5 (19.6)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
Trang 7Table.3 Effect of management modules on thrips population of onion during rabi, 2014-15 and
2015-16 (Mean of 7 replications)
2014-15
2015-16
Pooled
2014-15
2015-16
Pooled
2014-15
2015-16 Pooled
(30.3)
5.5 (30.2)
5.5 (30.3)
4.3 (17.9)
3.5 (12.1)
3.9 (15.0)
5.5 (30.4)
5.5 (30.0)
5.5 (30.2)
(18.5)
4.2 (16.8)
4.4 (17.7)
3.9 (14.7)
4.5 (19.9)
4.2 (17.3)
5.7 (31.9)
5.6 (31.0)
5.6 (31.5)
(31.3)
6.3 (38.8)
5.9 (35.0)
5.9 (34.9)
6.1 (36.5)
6.0 (35.7)
6.2 (37.9)
5.7 (32.3)
6.0 (35.1) SEm (±) 0.05 0.10 0.05 0.08 0.10 0.06 0.08 0.12 0.07 LSD (0.05) 0.15 0.31 0.15 0.25 0.31 0.18 0.25 NS 0.22
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
Note: Data in the parentheses indicate original values Data shown in the table are (x+0.5) square root transformed values M1: IPM module, M2: Farmers’ practices and M 3 : Control
Table.4 Effect of management modules on thrips population of onion during rabi, 2014-15 and
2015-16 (Mean of 7 replications)
(9.8)
3.3 (10.2)
3.2 (10.0)
3.0 (8.6)
2.6 (6.5)
2.8 (7.5)
(17.2)
4.5 (20.0)
4.4 (18.6)
3.7 (13.2)
3.3 (10.7)
3.5 (12.0)
(37.7)
5.2 (26.9)
5.7 (32.2)
5.3 (27.8)
4.5 (20.5)
4.9 (24.1)
Note: Data in the parentheses indicate original values Data shown in the table are (x+0.5) square root transformed values M1: IPM module, M2: Farmers’ practices and M 3 : Control
Trang 8Table.5 Effect of management modules on population of thrips per square inch of blue sticky
trap installed in onion crop field during rabi, 2014-15 and 2015-16
Modules Population of T tabaci per square inch area of blue sticky trap
2014-15
2015-16
Pooled
2014-15
2015-16
Pooled
2014-15
2015-16 Pooled
(0.0)
0.7 (0.0)
0.7 (0.0)
0.8 (0.1)
0.7 (0.1)
0.7 (0.1)
0.8 (0.2)
0.8 (0.1)
0.8 (0.1)
(0.0)
0.7 (0.1)
0.7 (0.1)
0.8 (0.2)
0.9 (0.2)
0.8 (0.2)
1.1 (0.7)
0.9 (0.3)
1.0 (0.5)
(0.1)
0.7 (0.0)
0.7 (0.1)
0.9 (0.3)
0.8 (0.2)
0.8 (0.2)
1.1 (0.7)
0.9 (0.3)
1.0 (0.5) SEm (±) 0.01 0.01 0.01 0.04 0.04 0.03 0.06 0.03 0.03
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
Note: Data in the parentheses indicate original values Data shown in the table are (x+0.5) square root transformed values M1: IPM module, M2: Farmers’ practices and M 3 : Control
Table.6 Effect of management modules on population of thrips per square inch of blue sticky
trap installed in onion crop field during rabi, 2014-15 and 2015-16
Modules Population of T tabaci per square inch area of blue sticky trap
2014-15
2015-16
Pooled
2014-15
2015-16
Pooled
2014-15
2015-16 Pooled
(0.3)
0.8 (0.2)
0.9 (0.3)
0.9 (0.4)
0.8 (0.2)
0.9 (0.3)
3.6 (12.6)
1.5 (1.8)
2.5 (7.2)
(1.2)
1.1 (0.7)
1.2 (0.9)
1.8 (2.7)
1.2 (0.9)
1.5 (1.8)
4.2 (17.0)
1.2 (1.1)
2.7 (9.0)
(1.2)
1.0 (0.6)
1.2 (0.9)
1.8 (2.9)
1.6 (2.0)
1.7 (2.5)
4.3 (18.0)
2.0 (3.4)
3.1 (10.7) SEm (±) 0.05 0.04 0.03 0.03 0.06 0.03 0.08 0.09 0.06 LSD (0.05) 0.16 0.13 0.11 0.09 0.19 0.11 0.25 0.26 0.18
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
Note: Data in the parentheses indicate original values Data shown in the table are (x+0.5) square root transformed values M1: IPM module, M2: Farmers’ practices and M 3 : Control
Trang 9Table.7 Effect of management modules on population of thrips per square inch of blue sticky
trap installed in onion crop field during rabi, 2014-15 and 2015-16
Modules Population of T tabaci per square inch area of blue sticky trap
2014-15
2015-16 Pooled
2014-15
2015-16 Pooled
2014-15
2015-16 Pooled
(17.8)
3.4 (11.1)
3.8 (14.5)
4.4 (19.3)
3.4 (11.4)
3.9 (15.3)
3.6 (12.8)
2.5 (5.9)
3.1 (9.4)
(12.9)
3.0 (8.3)
3.3 (10.6)
4.4 (18.8)
3.3 (10.7)
3.9 (14.8)
3.7 (13.0)
2.9 (8.2)
3.3 (10.6)
(18.7)
3.5 (12.0)
3.9 (15.3)
4.0 (15.4)
4.0 (15.4)
4.0 (15.4)
4.2 (17.1)
4.0 (15.8)
4.1 (16.4)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
Note: Data in the parentheses indicate original values Data shown in the table are (x+0.5) square root transformed
values M1: IPM module, M2: Farmers’ practices and M 3 : Control
Table.8 Effect of management modules on population of thrips per square inch of blue sticky
trap installed in onion crop field during rabi, 2014-15 and 2015-16
Modules Population of T tabaci per square inch area of blue sticky trap
2014-15
2015-16
Pooled
2014-15
2015-16
Pooled
2014-15
2015-16 Pooled
(10.7)
4.3 (17.6)
3.8 (14.2)
2.5 (5.6)
2.8 (7.6)
2.6 (6.6)
2.1 (4.1)
2.2 (4.2)
2.1 (4.1)
(18.6)
4.3 (18.1)
4.3 (18.4)
2.9 (8.1)
3.2 (9.5)
3.0 (8.8)
2.7 (7.1)
2.6 (6.4)
2.7 (6.7)
(17.8)
5.1 (26.1)
4.7 (22.0)
3.8 (13.9)
5.2 (27.0)
4.5 (20.5)
3.1 (9.4)
3.7 (13.3)
3.4 (11.4)
LSD (0.05) 0.12 0.46 0.24 0.43 0.39 0.29 0.31 0.14 0.17
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
SEm (±)
LSD (0.05)
Note: Data in the parentheses indicate original values Data shown in the table are (x+0.5) square root transformed values M1: IPM module, M2: Farmers’ practices and M 3 : Control
Trang 10Table.9 Effect of thrips management modules on number of onion bulbs during rabi, 2014-15
and 2015-16
Table.10 Effect of thrips management modules on fresh weight of onion bulb during rabi,
2014-15 and 202014-15-16
(kg/plot)
Fresh weight of bulb
(q/ha) 2014-15 2015-16 Pooled 2014-15 2015-16 Pooled
Note: Onion equivalent yield was calculated considering market price of onion as Rs 400/q, wheat grain as Rs 1450/q and maize grain as Rs 1500/q
Table.11 Effect of thrips management modules on dry weight of onion bulb during rabi,
2014-15 and 202014-15-16
(kg/plot)
Dry weight of bulb (q/ha)
Note: Onion equivalent yield was calculated considering market price of onion as Rs 500/q, wheat grain as Rs 1450/q and maize grain as Rs 1500/q, mean grain yield of wheat and maize were 5.87q and 22.78q in 3030 sq m area